Hydantoin derivatives for the treatment of obstructive airway diseases

ABSTRACT

The invention provides compounds of formula (I), wherein R 1  and R 2  are as defined in the specification; processes for their preparation; pharmaceutical compositions containing them; a process for preparing the pharmaceutical compositions; and their use in therapy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/571,637, filed on Jan. 4, 2007 (now U.S. Pat. No. 7,648,992), whichis the United States National Stage of International Application No.PCT/SE2005/001092, filed Jul. 4, 2005, which claims the benefit ofSwedish Application Serial No. 0401762-0, filed Jul. 5, 2004; each ofthese prior applications is incorporated herein by reference in itsentirety.

The present invention relates to novel hydantoin derivatives, processesfor their preparation, pharmaceutical compositions containing them andtheir use in therapy.

Metalloproteinases are a superfamily of proteinases (enzymes) whosenumbers in recent years have increased dramatically. Based on structuraland functional considerations these enzymes have been classified intofamilies and subfamilies as described in N. M. Hooper to (1994) FEBSLetters 354:1-6. Examples of metalloproteinases include the matrixmetalloproteinases (MMPs) such as the collagenases (MMP1, MMP8, MMP13),the gelatinases (MMP2, MMP9), the stromelysins (MMP3, MMP10, MMP11),matrilysin (MMP7), metalloelastase (MMP 12), enamelysin (MMP 19), theMT-MMPs (MMP 14, MMP15, MMP16, MMP17); the reprolysin or adamalysin orMDC family which includes the secretases and sheddases such as TNFconverting enzymes (ADAM10 and TACE); the astacin family which includeenzymes such as procollagen processing proteinase (PCP); and othermetalloproteinases such as aggrecanase, the endothelin converting enzymefamily and the angiotensin converting enzyme family.

Metalloproteinases are believed to be important in a plethora ofphysiological disease processes that involve tissue remodelling such asembryonic development, bone formation and uterine remodelling duringmenstruation. This is based on the ability of the metalloproteinases tocleave a broad range of matrix substrates such as collagen, proteoglycanand fibronectin. Metalloproteinases are also believed to be important inthe processing, or secretion, of biological important cell mediators,such as tumour necrosis factor (TNF); and the post translationalproteolysis processing, or shedding, of biologically important membraneproteins, such as the low affinity IgE receptor CD23 (for a morecomplete list see N. M. Hooper et al., (1997) Biochem. J. 321:265-279).

Metalloproteinases have been associated with many diseases orconditions. Inhibition of the activity of one or more metalloproteinasesmay well be of benefit in these diseases or conditions, for example:various inflammatory and allergic diseases such as, inflammation of thejoint (especially rheumatoid arthritis, osteoarthritis and gout),inflammation of the gastro-intestinal tract (especially inflammatorybowel disease, ulcerative colitis and gastritis), inflammation of theskin (especially psoriasis, eczema, dermatitis); in tumour metastasis orinvasion; in disease associated with uncontrolled degradation of theextracellular matrix such as osteoarthritis; in bone resorptive disease(such as osteoporosis and Paget's disease); in diseases associated withaberrant angiogenesis; the enhanced collagen remodelling associated withdiabetes, periodontal disease (such as gingivitis), corneal ulceration,ulceration of the skin, post-operative conditions (such as colonicanastomosis) and dermal wound healing; demyelinating diseases of thecentral and peripheral nervous systems (such as multiple sclerosis);Alzheimer's disease; extracellular matrix remodelling observed incardiovascular diseases such as restenosis and atheroscelerosis; asthma;rhinitis; and chronic obstructive pulmonary diseases (COPD).

MMP 12, also known as macrophage elastase or metalloelastase, wasinitially cloned in the mouse by Shapiro et al [1992, Journal ofBiological Chemistry 267: 4664] and in man by the same group in 1995.MMP 12 is preferentially expressed in activated macrophages, and hasbeen shown to be secreted from alveolar macrophages from smokers[Shapiro et al, 1993, Journal of Biological Chemistry, 268: 23824] aswell as in foam cells in atherosclerotic lesions [Matsumoto et al, 1998,Am. J. Pathol. 153: 109]. A mouse model of COPD is based on challenge ofmice with cigarette smoke for six months, two cigarettes a day six daysa week. Wild-type mice developed pulmonary emphysema after thistreatment. When MMP12 knock-out mice were tested in this model theydeveloped no significant emphysema, strongly indicating that MMP 12 is akey enzyme in the COPD pathogenesis. The role of MMPs such as MMP12 inCOPD (emphysema and bronchitis) is discussed in Anderson and Shinagawa,1999, Current Opinion in Anti-inflammatory and ImmunomodulatoryInvestigational Drugs 1(1): 29-38. It was recently discovered thatsmoking increases macrophage infiltration and macrophage-derived MMP-12expression in human carotid artery plaques Kangavari [Matetzky S,Fishbein M C et al., Circulation 102:(18), 36-39 Suppl. S, Oct. 31,2000].

MMP9 (Gelatinase B; 92 kDa TypeIV Collagenase; 92 kDa Gelatinase) is asecreted protein which was first purified, then cloned and sequenced, in1989 [S. M. Wilhelm et al (1989) J. Biol. Chem. 264 (29): 17213-17221;published erratum in J. Biol. Chem. (1990) 265 (36): 22570]. A recentreview of MMP9 provides an excellent source for detailed information andreferences on this protease: T. H. Vu & Z. Werb (1998) (In: MatrixMetalloproteinases, 1998, edited by W. C. Parks & R. P. Mecham, pp.115-148, Academic Press. ISBN 0-12-545090-7). The following points aredrawn from that review by T. H. Vu & Z. Werb (1998).

The expression of MMP9 is restricted normally to a few cell types,including trophoblasts, osteoclasts, neutrophils and macrophages.However, the expression can be induced in these same cells and in othercell types by several mediators, including exposure of the cells togrowth factors or cytokines. These are the same mediators oftenimplicated in initiating an inflammatory response. As with othersecreted MMPs, MMP9 is released as an inactive Pro-enzyme which issubsequently cleaved to form the enzymatically active enzyme. Theproteases required for this activation in vivo are not known. Thebalance of active MMP9 versus inactive enzyme is further regulated invivo by interaction with TIMP-1 (Tissue Inhibitor of Metalloproteinases-1), a naturally-occurring protein. TIMP-1 binds to the C-terminalregion of MMP9, leading to inhibition of the catalytic domain of MMP9.The balance of induced expression of ProMMP9, cleavage of Pro- to activeMMP9 and the presence of TIMP-1 combine to determine the amount ofcatalytically active MMP9 which is present at a local site.Proteolytically active MMP9 attacks substrates which include gelatin,elastin, and native Type IV and Type V collagens; it has no activityagainst native Type I collagen, proteoglycans or laminins.

There has been a growing body of data implicating roles for MMP9 invarious physiological and pathological processes. Physiological rolesinclude the invasion of embryonic trophoblasts through the uterineepithelium in the early stages of embryonic implantation; some role inthe growth and development of bones; and migration of inflammatory cellsfrom the vasculature into tissues.

MMP9 release, measured using enzyme immunoassay, was significantlyenhanced in fluids and in AM supernatants from untreated asthmaticscompared with those from other populations [Am. J. Resp. Cell & Mol.Biol., November 1997, 17 (5):583-591]. Also, increased MMP9 expressionhas been observed in certain other pathological conditions, therebyimplicating MMP9 in disease processes such as COPD, arthritis, tumourmetastasis, Alzheimer's disease, multiple sclerosis, and plaque rupturein atherosclerosis leading to acute coronary conditions such asmyocardial infarction.

A number of metalloproteinase inhibitors are known (see for example thereviews of MMP inhibitors by Beckett R. P. and Whittaker M., 1998, Exp.Opin. Ther. Patents, 8(3):259-282, and by Whittaker M. et al, 1999,Chemical Reviews 99(9):2735-2776).

WO 02/074767 discloses hydantoin derivatives of formula

that are useful as MMP inhibitors, particularly as potent MMP12inhibitors. The following three compounds are specifically disclosed inWO 02/074767

We have now discovered a group of compounds that are inhibitors ofmetalloproteinases and are of particular interest in inhibiting MMPssuch as MMP12 and MMP9. The compounds of the present invention havebeneficial potency, selectivity and/or pharmacokinetic properties. Thecompounds of the present invention are within the generic scope of WO02/074767 but are of a type not specifically exemplified therein.

In accordance with the present invention, there is therefore provided acompound of formula (I)

wherein

R¹ represents C1 to 2 alkyl, cyclopropyl, OCH₃, SCH₃ or OCF₃; said alkylor cyclopropyl group being optionally further substituted by one or morefluoro atoms; and

R² represents C1 to 3 alkyl; and pharmaceutically acceptable saltsthereof.

The compounds of formula (I) may exist in enantiomeric forms. It is tobe understood that all enantiomers, diastereomers, racemates andmixtures thereof are included within the scope of the invention.

Compounds of formula (I) may also exist in various tautomeric forms. Allpossible tautomeric forms and mixtures thereof are included within thescope of the invention.

In one embodiment, R ¹ represents C1 to 2 alkyl or cyclopropyl; saidalkyl or cyclopropyl group being optionally further substituted by oneor more fluoro atoms.

In another embodiment, R¹ represents C1 to 2 alkyl optionally furthersubstituted by one or more fluoro atoms.

In one embodiment, R¹ represents cyclopropyl optionally furthersubstituted by one or more fluoro atoms.

In one embodiment, R¹ represents cyclopropyl.

In one embodiment, R¹ represents trifluoromethyl.

In one embodiment, R¹ represents OCH₃ or SCH₃.

In one embodiment, R² represents methyl or ethyl. In one embodiment, R²represents methyl.

In one embodiment, R¹ represents C1 to 2 alkyl or cyclopropyl; saidalkyl or cyclopropyl group being optionally further substituted by oneor more fluoro atoms and R² represents methyl or ethyl.

In one embodiment, R¹ represents C1 to 2 alkyl or cyclopropyl; saidalkyl or cyclopropyl group being optionally further substituted by oneor more fluoro atoms and R² represents methyl.

In one embodiment, R¹ represents C1 to 2 alkyl optionally furthersubstituted by one or more fluoro atoms and R² represents methyl orethyl.

In one embodiment, R¹ represents CF₃ and R² represents methyl or ethyl.

In one embodiment, R¹ represents cyclopropyl and R² represents methyl orethyl.

Unless otherwise indicated, the term “C1 to 3 alkyl” referred to hereindenotes a straight or branched chain alkyl group having from 1 to 3carbon atoms. Examples of such groups include methyl, ethyl, n-propyland i-propyl. The term “C1 to 2 alkyl” denotes methyl or ethyl.

Examples of a C1 to 2 alkyl optionally further substituted by one ormore fluoro atoms include CF₃, CH₂F, CH₂CF₃, CF₂CH₃ and CF₂CF₃.

Examples of a cyclopropyl ring optionally further substituted by one ormore fluoro atoms include 1-fluoro-l-cyclopropyl,2,2-difluoro-l-cyclopropyl and 2,3-difluoro-1 -cyclopropyl:

Examples of compounds of the invention include:

-   (5S)-5-({[4-[(2-cyclopropylpyrimidin-5-yl)ethynyl]-3,6-dihydropyridin-1(2H)    -yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione;-   (5S)-5-methyl-5-({[4-{[2-(methylthio)pyrimidin-5-yl]ethynyl}-3,6-dihydropyridin-1(2H)    -yl]sulfonyl}methyl)imidazolidine-2,4-dione;-   (5S)-5-methyl-5-({[4-{[2-(trifluoromethyl)pyrimidin    -5-yl]ethynyl}-3,6-dihydropyridin    -1(2H)-yl]sulfonyl}methyl)imidazolidine-2,4-dione;-   (5S)-5-methyl-5-({[4-[(2-methylpyrimidin-5-yl)ethynyl]-3,6-dihydropyridin-1(2H)    -yl]sulfonyl}methyl)imidazolidine-2,4-dione;-   (5S)-5-({[4-[(2-ethylpyrimidin-5-yl)ethynyl]-3,6-dihydropyridin-1(2H)    -yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione;-   (5S)-5-({[4-[(2-methoxypyrimidin-5-yl)ethynyl]-3,6-dihydropyridin-1(2H)    -yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione;-   and pharmaceutically acceptable salts thereof.

Each exemplified compound represents a particular and independent aspectof the invention.

The compounds of formula (I) may exist in enantiomeric forms. Therefore,all enantiomers, diastereomers, racemates and mixtures thereof areincluded within the scope of the invention. The various optical isomersmay be isolated by separation of a racemic mixture of the compoundsusing conventional techniques, for example, fractional crystallisation,or HPLC. Alternatively the optical isomers may be obtained by asymmetricsynthesis, or by synthesis from optically active starting materials.

Where optically isomers exist in the compounds of the invention, wedisclose all individual optically active forms and combinations of theseas individual specific embodiments of the invention, as well as theircorresponding racemates.

Preferably the compounds of formula (I) have (5S)-stereochemistry asshown below:

Where tautomers exist in the compounds of the invention, we disclose allindividual tautomeric forms and combinations of these as individualspecific embodiments of the invention.

The present invention includes compounds of formula (I) in the form ofsalts. Suitable salts include those formed with organic or inorganicacids or organic or inorganic bases. Such salts will normally bepharmaceutically acceptable salts although non-pharmaceutically toacceptable salts may be of utility in the preparation and purificationof particular compounds. Such salts include acid addition salts such ashydrochloride, hydrobromide, citrate, tosylate and maleate salts andsalts formed with phosphoric acid or sulphuric acid. In another aspectsuitable salts are base salts such as an alkali metal salt, for example,sodium or potassium, an alkaline earth metal salt, for example, calciumor magnesium, or an organic amine salt, for example, triethylamine.

Salts of compounds of formula (I) may be formed by reacting the freebase or another salt thereof with one or more equivalents of anappropriate acid or base.

The compounds of formula (I) are useful because they possesspharmacological acivity in animals and are thus potentially useful aspharmaceuticals. In particular, the compounds of the invention aremetalloproteinase inhibitors and may thus be used in the treatment ofdiseases or conditions mediated by MMP12 and/or MMP9 such as asthma,rhinitis, chronic obstructive pulmonary diseases (COPD), arthritis (suchas rheumatoid arthritis and osteoarthritis), atherosclerosis andrestenosis, cancer, invasion and metastasis, diseases involving tissuedestruction, loosening of hip joint replacements, periodontal disease,fibrotic disease, infarction and heart disease, liver and renalfibrosis, endometriosis, diseases related to the weakening of theextracellular matrix, heart failure, aortic aneurysms, CNS relateddiseases such as Alzheimer's disease and Multiple Sclerosis (MS), andhematological disorders.

In general, the compounds of the present invention are potent inhibitorsof MMP9 and MMP 12. The compounds of the present invention also showgood selectivity with respect to a relative lack of inhibition ofvarious other MMPs such as MMP8, MMP14 and MMP19. In addition, thecompounds of the present invention also, in general, have improved log Dvalues, in particular, having log D values in the range of 0.5<logD<2.0. Log D is a parameter that reflects the lipophilicity of acompound at physiological pH. As a consequence of these favourable log Dvalues, the compounds of the present invention possess improvedsolubility characteristics and reduced plasma protein binding, leadingto improved pharmacokinetic and pharmacodynamic properties.

Accordingly, the present invention provides a compound of formula (I),or a pharmaceutically acceptable salt thereof, as hereinbefore definedfor use in therapy.

In another aspect, the invention provides the use of a compound offormula (I), or a pharmaceutically acceptable salt thereof, ashereinbefore defined in the manufacture of a medicament for use intherapy.

In another aspect, the invention provides the use of a compound offormula (I), or a pharmaceutically acceptable salt thereof, ashereinbefore defined in the manufacture of a medicament for use in thetreatment of diseases or conditions in which inhibition of MMP12 and/orMMP9 is beneficial.

In another aspect, the invention provides the use of a compound offormula (I), or a pharmaceutically acceptable salt thereof, ashereinbefore defined in the manufacture of a medicament for use in thetreatment of inflammatory disease.

In another aspect, the invention provides the use of a compound offormula (I), or a pharmaceutically acceptable salt thereof, ashereinbefore defined in the manufacture of a medicament for use in thetreatment of an obstructive airways disease such as asthma or COPD.

In the context of the present specification, the term “therapy” alsoincludes “prophylaxis” unless there are specific indications to thecontrary. The terms “therapeutic” and “therapeutically” should beconstrued accordingly.

Prophylaxis is expected to be particularly relevant to the treatment ofpersons who have suffered a previous episode of, or are otherwiseconsidered to be at increased risk of, the disease or condition inquestion. Persons at risk of developing a particular disease orcondition generally include those having a family history of the diseaseor condition, or those who have been identified by genetic testing orscreening to be particularly susceptible to developing the disease orcondition.

The invention further provides a method of treating a disease orcondition in which inhibition of MMP12 and/or MMP9 is beneficial whichcomprises administering to a patient a therapeutically effective amountof a compound of formula (I) or a pharmaceutically acceptable saltthereof as hereinbefore defined.

The invention also provides a method of treating an obstructive airwaysdisease, for example, asthma or COPD, which comprises administering to apatient a therapeutically effective amount of a compound of formula (I)or a pharmaceutically acceptable salt thereof as hereinbefore defined.

For the above-mentioned therapeutic uses the dosage administered will,of course, vary with the compound employed, the mode of administration,the treatment desired and the disorder to be treated. The daily dosageof the compound of formula (I)/salt (active ingredient) may be in therange from 0.001 mg/kg to 75 mg/kg, in particular from 0.5 mg/kg to 30mg/kg. This daily dose may be given in divided doses as necessary.

Typically unit dosage forms will contain about 1 mg to 500 mg of acompound of this invention.

The compounds of formula (I) and pharmaceutically acceptable saltsthereof may be used on their own but will generally be administered inthe form of a pharmaceutical composition in which the formula (I)compound/salt (active ingredient) is in association with apharmaceutically acceptable adjuvant, diluent or carrier. Depending onthe mode of administration, the pharmaceutical composition willpreferably comprise from 0.05 to 99% w (per cent by weight), morepreferably from 0.10 to 70% w, of active ingredient, and, from 1 to99.95% w, more preferably from 30 to 99.90% w, of a pharmaceuticallyacceptable adjuvant, diluent or carrier, all percentages by weight beingbased on total composition. Conventional procedures for the selectionand preparation of suitable pharmaceutical formulations are describedin, for example, “Pharmaceuticals—The Science of Dosage Form Designs”,M. E. Aulton, Churchill Livingstone, 1988.

Thus, the present invention also provides a pharmaceutical compositioncomprising a compound of formula (I) or a pharmaceutically acceptablesalt thereof as hereinbefore defined in association with apharmaceutically acceptable adjuvant, diluent or carrier.

The invention further provides a process for the preparation of apharmaceutical composition of the invention which comprises mixing acompound of formula (I) or a pharmaceutically acceptable salt thereof ashereinbefore defined with a pharmaceutically acceptable adjuvant,diluent or carrier.

The pharmaceutical compositions of this invention may be administered ina standard manner for the disease or condition that it is desired totreat, for example by oral, topical, parenteral, buccal, nasal, vaginalor rectal administration or by inhalation. For these purposes thecompounds of this invention may be formulated by means known in the artinto the form of, for example, tablets, capsules, aqueous or oilysolutions, suspensions, emulsions, creams, ointments, gels, nasalsprays, suppositories, finely divided powders or aerosols forinhalation, and for parenteral use (including intravenous, intramuscularor infusion) sterile aqueous or oily solutions or suspensions or sterileemulsions.

In addition to the compounds of the present invention the pharmaceuticalcomposition of this invention may also contain, or be co-administered(simultaneously or sequentially) with, one or more pharmacologicalagents of value in treating one or more diseases or conditions referredto hereinabove such as “Symbicort” (trade mark) product.

The present invention further provides a process for the preparation ofa compound of formula (I) or a pharmaceutically acceptable salt thereofas defined above which, comprises:

-   a) reaction of a compound of formula (II)

wherein R² is as defined in formula (I) and L¹ represents a leavinggroup, with a compound of formula (III) (or a salt thereof)

wherein R¹ is as defined in formula (I); or

-   b) reaction of a compound of formula (X)

where R² is as defined in formula (I), R³ is H or a suitable protectinggroup and X is a leaving group such as halide or triflate; with anacetylenic compound of formula (IX)

wherein R¹ is as defined in formula (I); or

-   c) reaction of a compound of formula (XI)

wherein R represents H or trimethylsilyl, R² is as defined in formula(I) and R³ represents H or a suitable protecting group; with an arylhalide or triflate of formula (VI)

wherein R¹ is as defined in formula (I) and X represents halide ortriflate; and optionally thereafter forming a pharmaceuticallyacceptable salt thereof

In the above process (a), suitable leaving groups L¹ include halo,particularly chloro. The reaction is preferably performed in a suitablesolvent optionally in the presence of an added base for a suitableperiod of time, typically 0.5 to 24 h, at ambient to reflux temperature.Typically solvents such as pyridine, dimethylformamide, tetrahydrofuran,acetonitrile or dichloromethane are used. When used, the added base maybe an organic base such as triethylamine, diisopropylethylamine,N-methylmorpholine or pyridine, or an inorganic base such as an alkalimetal carbonate. The reaction is typically conducted at ambienttemperature for 0.5 to 16 h, or until completion of the reaction hasbeen achieved, as determined by chromatographic or spectroscopicmethods. Reactions of sulfonyl halides with various primary andsecondary amines are well known in the literature, and the variations ofthe conditions will be evident for those skilled in the art.

Sulfonylchlorides of formula (II) (wherein L¹ represents chlorine) areconveniently prepared by oxidative chlorination of compounds of formula(IV)

using methods that will be readily apparent to those skilled in the art(Mosher, J., J. Org. Chem. 1958. 23, 1257; Griffith, O., J. Biol. Chem.1983. 258, (3), 1591; WO 02/074767).

Compounds of formula (III) can be prepared by various methods describedin the literature or variations thereon as will be appreciated by thoseskilled in the art of synthetic organic chemistry. Suitable methodsinclude, but are not limited to, those described below and are shown inScheme 1.

In Scheme 1, PG represents a suitable protecting group such as t-Boc; Xrepresents a leaving group such as a halide or a triflate; R representshydrogen or trimethylsilyl; tms represents trimethylsilyl; Ar representsa 5-pyrimidinyl ring substituted at the 2-position by R¹; and R¹ is asdefined in formula (I).

The reaction between the aryl- or vinyl derivative [(V) or (VD] and anacetylene [(VII), (VIII) or (IX)] can be accomplished, optionally in asuitable solvent, using a catalyst such as a suitable palladium salt,for example, PdCl₂(PPh₃)₂, with/or without an added copper salt and withan amine base such as piperidine, triethylamine, diisopropylamine ordiisopropylethylamine. When used, the added solvent may be, for example,tetrahydrofuran, acetonitrile or N,N-dimethylformamide. The reaction isconducted at ambient to reflux temperature for 20 minutes to severalhours until chromatographic or spectroscopic methods indicate completionof the reaction. Palladium catalysed reactions involving acetyleniccompounds are well known in the literature, and variations of theconditions will be evident for those skilled in the art. Generalmethodology of this type is described in, for example, Brandsma, L.,Synthesis of Acetylenes, Allenes and Cumulenes: Methods and Techniques,2004, Elsiever Academic Press, chapter 16, pages 293-317; TransitionMetals-Catalysed Couplings of Acetylenes with sp ²-halides, Sonogashira,K., J. Organomet. Chem., 2002, 653, 46-49; Tykwinski, R. R., Angew.Chem. Int. Ed., 2003, 42, 1566-1568.

The vinyl triflate (V) wherein X is O-triflate and PG is t-Boc can beprepared as described in the literature (Wustrow, D. J., Synthesis,1991, 993-995).

Suitable substituted pyrimidinyl halides or triflates of formula (VI)can be prepared by various methods described in the literature, forexample, Budesinsky, Z. et al., Coll. Czech. Chem. Commun., 1949, 14,223-235; Takahashi et al., Chem. Pharm. Bull., 1958, 6, 334-337; U.S.Pat. No. 4,558,039.

The acetylenic compound (VIII) can be prepared from the triflate (V) viaa palladium catalysed coupling reaction with trimethylsilylacetylenefollowed by, if necessary, deprotection of the trimethylsilyl groupusing, for example, potassium fluoride in a suitable solvent.Alternatively, preparation of compound (VIII) wherein R is H and PG ist-Boc can be accomplished by dehydrating a compound of formula (VII),for example, by mesylation followed by treatment with a suitable base,for example, diisopropylethylamine.

Acetylenic heteroaryl compounds of formula (IX) can be prepared byvarious methods described in the literature.

In process (b), the reactions are carried out using methods similar tothose described above for the preparation of compounds of formula(VIII). If necessary, one nitrogen in the hydantoin ring of compounds offormula (X) can be protected using SEMC1 (R³=SEM) before the palladiumcatalysed reaction is performed. Compounds of formula (X) can beprepared by acid catalysed deprotection of compounds of formula (V)(PG=t-Boc), followed by reaction with a compound of formula (II), in thesame way as described above to for the preparation of compounds offormula (I).

In process (c), the reactions are carried out in a similar manner tothose described above for the preparation of compounds of formula(VIII). If necessary, one nitrogen of the hydantoin ring of compounds offormula (XI) can be protected using SEMC1 (R³=SEM) before the palladiumcatalysed reaction is performed. Compound (XI) is conveniently preparedfrom compound (VIII) wherein R is trimethylsilyl and PG is t-Boc by acidcatalysed removal of the t-Boc group (for example, using acetyl chloridein methanol), followed by reaction with a compound of formula (II), asdescribed above for the reaction between compounds of formulae (II) and(III).

It will be appreciated by those skilled in the art that in the processesof the present invention certain potentially reactive functional groupssuch as hydroxyl or amino groups in the starting reagents orintermediate compounds may need to be protected by suitable protectinggroups. Thus, the preparation of the compounds of the invention mayinvolve, at various stages, the addition and removal of one or moreprotecting groups.

Suitable protecting groups and details of processes for adding andremoving such groups are described in ‘Protective Groups in OrganicChemistry’, edited by J. W. F. McOmie, Plenum Press (1973) and‘Protective Groups in Organic Synthesis’, 3rd edition, T. W. Greene andP. G. M. Wuts, Wiley-Interscience (1999).

The compounds of the invention and intermediates thereto may be isolatedfrom their reaction mixtures and, if necessary further purified, byusing standard techniques.

The present invention will now be further explained by reference to thefollowing illustrative examples.

General Methods

¹H NMR and ¹³C NMR spectra were recorded on a Varian Inova 400 MHz or aVarian to Mercury-VX 300 MHz instrument. The central peaks ofchloroform-d (δ_(H) 7.27 ppm), dimethylsulfoxide-d₆ (δ_(H) 2.50 ppm),acetonitrile-d₃ (δ_(H) 1.95 ppm) or methanol-d₄ (δ_(H) 3.31 ppm) wereused as internal references. Column chromatography was carried out usingsilica gel (0.040-0.063 mm, Merck). A Kromasil KR-100-5-C₁₈ column(250×20 mm, Akzo Nobel) and mixtures of acetonitrile/water with 0.1% TFAat a flow rate of 10 mL/min were used for preparative HPLC. Unlessstated otherwise, starting materials were commercially available. Allsolvents and commercial reagents were of laboratory grade and were usedas received.

The following method was used for LC/MS analysis:

-   Instrument Agilent 1100; Column Waters Symmetry 2.1×30 mm; Mass    APCI; Flow rate 0.7 mL/min; Wavelength 254 or 220 nm; Solvent A:    water+0.1% TFA; Solvent B: acetonitrile+0.1% TFA ; Gradient 15-95%/B    2.7 min, 95% B 0.3 min.

The following method was used for LC analysis:

-   p Method A. Instrument Agilent 1100; Column: Kromasil C18 100×3 mm,    5μ particle size, Solvent A: 0.1% TFA/water, Solvent B: 0.08%    TFA/acetonitrile Flow rate 1 mL/min, Gradient 10-100%/B 20 min, 100%    B 1 min. Absorption was measured at 220, 254 and 280 nm.-   Method B. Instrument Agilent 1100; Column: XTerra C 8, 100×3 mm, 5μ    particle size, Solvent A: 15 mM NH₃/water, Solvent B: acetonitrile    Flow rate 1 mL/min, Gradient 10-100%/B 20 min, 100% B 1 min.    Absorption was measured at 220, 254 and 280 nm.    Abbreviations:-   Ac acetyl-   DMF N,N-dimethylformamide-   DMSO dimethyl sulfoxide-   eq. equivalent-   Et ethyl-   LDA lithium diisopropyl amide-   Me methyl-   MS mass spectroscopy-   tert tertiary-   THF tetrahydrofuran-   TFA trifluoroacetic acid

EXAMPLE 1(5S)-5-({[4-[(2-Cyclopropylpyrimidin-5-yl)ethynyl]-3,6-dihydropyridin-1(2H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione

The title compound was prepared following the general method of Yamanakaet al, Synth. Commun., 1983, 312-314. To 5-bromo-2-cyclopropylpyrimidine(110 mg, 0.55 mmol) and (5S)-5-({[(4-ethynyl-3,6-dihydropyridin-1(2H)-yl)sulfonyl]methyl}-5-methylimidazolidine-2,4-dione (180 mg, 0.61 mmol)in THF (3 mL) was added Et₃N (1 mL) and DMF (1 mL) at 35° C. After asolution was formed, CuI (4 mol %) and PdCl₂(PPh₃)₂ (2 mol %) were addedand the mixture was heated at 72° C. for 6 hours. The mixture waspartitioned between EtOAc (15 mL) and water (10 mL), and the aqueouslayer was extracted three times with EtOAc. The combined organic layerswere dried and concentrated to give the crude product as a yellow oil.The title compound (65 mg) was obtained by purification usingpreparative HPLC.

¹H-NMR (DMSO-d₆): δ 10.75 (1H, s); 8.72 (2H, s); 8.03 (1H, s); 6.28 (1H,m); 3.84 (2H, m); 3.47 (2H, q); 3.30 (2H, m); 2.37 (2H, m); 2.21 (1H,m); 1.33 (3H, s); 1.10 (2H, m); 1.02 (2H, m).

APCI-MS m/z: 416 [MH⁺].

a) 5-Bromo-2-cyclopropylpyrimidine

5-Bromo-2-cyclopropylpyrimidine was prepared by the method ofBudesinsky, Z., Coll. Czech. Chem. Commun., 1949, 14, 223-235.Cyclopropanecarboximidamide hydrochloride (2.5 g, 20.7 mmol) wasdissolved in EtOH (4 mL), freshly prepared 4.1M NaOEt in EtOH (4.8 mL)was added followed by mucobromic acid (2.7 g, 10.3 mmol). The mixturewas heated to 56° C. for 30 minutes, more NaOEt in EtOH (4.1M, 3.2 mL)was added and the reaction was stirred at 56° C. for another 15 minutesand then at room temperature overnight. The solvent was evaporated off,aqueous HCl (2M, 10 mL) was added and the brown solid was filtered off.The aqueous layer was extracted three times with dichloromethane. Thecombined organic layers were dried and concentrated to give a brown oilthat together with the solid gave crude intermediate5-bromo-2-cyclopropylpyrimidine-4-carboxylic acid (1.6 g). The crudeintermediate was heated at 140° C. for 8 minutes to give a brown stickyoil that was then partly dissolved in dichloromethane. The solution wasdecanted from the mixture and concentrated to give the subtitle compoundas an oil (673 mg).

¹H-NMR (CDCl₃): δ 8.61 (2H, s); 2.25 (1H, m); 1.13 (4H, m).

APCI-MS m/z: 199/201 1:1 [MH⁺].

b) (5S)-5-{[(4-Ethynyl-3,6-dihydropyridin-1(2H)-yl)sulfonyl]methyl}-5-methylimidazolidine-2,4-dione

(5S)-5-Methyl-5-({[4-[(trimethylsilyl)ethynyl]-3,6-dihydropyridin-1(2H)-yl]sulfonyl}methyl)imidazolidine-2,4-dione (2.27 g, 6.0 mmol) andpotassium fluoride (1.07 g, 18.4 mmol) were stirred overnight at roomtemperature in methanol (50 mL). The solvent was evaporated off, theresidue dissolved in EtOAc, washed with water followed by brine, dried(sodium sulphate) and evaporated. The residue was purified by columnchromatography eluting with iso-hexane/EtOAc 1:1 to give a solid product(1.81 g).

¹H NMR (CDCl₃) δ 1.66 (3H, s), 2.37 (2H, dt), 2.95 (1H, s), 3.24-3.50(4H, m), 3.89 (2H, t), 6.11 (1H, s), 6.68 (1H, s), 8.75 (1H, s).

APCI-MS m/z: 298 [MH⁺].

c)(5S)-5-Methyl-5-({[4-[(trimethylsilyl)ethynyl]-3,6-dihydropyridin-1(2H)-yl]sulfonyl}methyl)imidazolidine-2,4-dione

4-[(Trimethylsilyl)ethynyl]-1,2,3,6-tetrahydropyridine hydrochloride(3.43 g, 15.9 mmol) was stirred in THF (100 mL) with[(4S)-4-methyl-2,5-dioxoimidazolidin -4-yl]methanesulfonyl chloride(3.39 g, 15 mmol) and cooled in an ice salt bath (temperature about −10°C.). N-Ethyldiisopropylamine (5.13 mL, 30 mmol) in THF (100 mL) wasadded dropwise over 2 hours and the mixture stirred a further 2 hours.The reaction mixture was washed with water, the aqueous layer extractedinto EtOAc (×2), the organic phases combined, washed with 2M HCl (×2),saturated bicarbonate solution (x2), followed by brine, dried (sodiumsulphate) and evaporated to give the crude product (5.06 g). This wasused without further purification.

¹H NMR (DMSO-d₆) δ 10.74 (1H, s), 8.01 (1H, s), 6.13 (1H, quintet), 3.75(2H, d), 3.44 (2H, dd), 3.23 (2H, t), 2.18-2.28 (2H, m), 1.32 (3H, s),1.32 (9H, s).

APCI-MS m/z: 370 [MH⁺].

d) 4-[(Trimethylsilyl)ethynyl]-1,2,3,6-tetrahydropyridine hydrochloride

tert-Butyl 4-[(trimethylsilyl)ethynyl]-3,6-dihydropyridine-1(2H)-carboxylate (2.75 g, 9.8 mmol) was stirred in methanol (10 mL) andacetyl chloride (2.1 mL, 29.2 mmol) was added dropwise. The temperaturerose from 18° C. to 30° C. during the addition, and the mixture was keptat 40° C. until there was no more starting material by tic. The mixturewas cooled to room temperature, EtOAc (15 mL) was added and the solidfiltered off to give an off-white solid (1.6 g).

¹H NMR (DMSO-d₆) δ 9.46 (2H, s), 6.09 (1H, quintet), 3.60 (2H, dd), 3.13(2H, t), 2.35 (2H, td), 0.17 (8H, s).

APCI-MS m/z: 180 [MH⁺].

e) tert-Butyl4-[trimethylsilyl)ethynyl]-3,6-dihydropyridine-1(2H)-carboxylate

Prepared from N-Boc-piperidin-4-one as in WO 96/05200.

¹H NMR (CDCl₃) δ 6.05 (1H, s), 3.94 (2H, dd), 3.47 (2H, t), 2.23 (2H,dq), 1.45 (10H), s), 0.15 (8H, s).

GCMS-MS m/z: 223 [M-55].

f) [(4S)-4-Methyl-2,5-dioxoimidazolidin-4-yl]methanesulfonyl chloride

Prepared according to methods described in the following publications:Mosher, J., J. Org. Chem. 1958. 23, 1257; Griffith, O., J. Biol. Chem.1983. 258, (3), 1591; and WO 02/074767.

EXAMPLE 2(5S)-5-Methyl-5-({[4-{[2-(methylthio)pyrimidin-5-yl]ethynyl}-3,6-dihydropyridin-1(2H)-yl]sulfonyl}methyl)imidazolidine-2,4-dione

The title compound was prepared by the general method described byNishihara et al., J. Org. Chem., 2000, 65, 1780-1787. To a solution of2-(methylthio)-5-[(trimethylsilyl)ethynyl]pyrimidine (0.55 g, 2.47 mmol)and1-{[(4-methyl-2,5-dioxoimidazolidin-4-yl)methyl]sulfonyl}-1,2,3,6-tetrahydropyridin-4-yltrifluoromethanesulfonate (0.94 g, 2.22 mmol) in DMF (5 mL) was addedCuI (10 mol %) and PdCl₂(PPh₃)₂ (5 mol %) and the mixture was heated at85° C. for 6 hours. The mixture was partitioned between EtOAc (20 mL)and water (10 mL), and the aqueous layer was extracted three times withEtOAc. The combined organic layers were washed with brine, water andconcentrated to a brown oil (1.6 g). The title compound was obtained asa solid (10 mg) following purification by preparative HPLC (using aXterra-Prep-MS-C18 (50×19) column with a 12 minutes gradient 5-35% ofacetonitrile in water with 0.06% NH₃).

¹H-NMR (DMSO-d₆): δ 10.75 (1H, s); 8.73 (2H, s); 8.02 (1H, s); 6.29 (1H,m); 3.84 (2H, m); 3.48 (2H, q); 3.30 (2H, m); 2.53 (3H, s); 2.38 (2H,m); 1.33 (3H, s).

APCI-MS m/z: 422 [MH⁺].

a) 5-Bromo-2-(methylthio)pyrimidine

The subtitle compound was prepared following a method by Takahashi etal., Chem. Pharm. Bull., 1958, 6, 334-337. To a solution of5-bromo-2-chloropyrimidine (1.0 g, 5.2 mmol) in EtOH was added sodiummethanethiolate (0.36 g, 5.2 mmol) at room temperature and the reactionmixture was stirred overnight. The mixture was partitioned between EtOAc(15 mL) and water (10 mL). The aqueous layer was extracted twice withEtOAc and washed with brine. The combined organic layers were dried andconcentrated to give the subtitle compound as a white solid (1.1 g).

¹H-NMR (CD₃OD): δ 8.66 (2H, s); 2.54 (3H, s).

APCI-MS m/z: 204/206 1:1 [MH⁺].

b) 2-(Methylthio)-5-[(trimethylsilyl)ethynyl]pyrimidine

The subtitle compound was prepared following a method by Yamanaka et al,Synth. Commun., 1983, 312-314. To 5-bromo-2-(methylthio)pyrimidine (0.60g, 2.9 mmol) in Et₃N (3 mL) was added DMF (0.5 mL), CuI (5 mol %) andPdCl₂(PPh₃)₂ (3 mol %). The mixture was heated at 95° C. for 12 hours ina sealed tube and then partitioned between Et₂O (30 mL) and water (10mL). The aqueous layer was extracted twice with Et₂O and the combinedorganic layers were washed with water, dried and concentrated to givethe crude product as a brown oil. The compound was purified by flashchromatography using a gradient of 10-60% EtOAc in heptane, which gavethe subtitle compound as a colourless oil (0.55 g).

¹H-NMR (CDCl₃): δ 8.56 (2H, s); 2.58 (3H, s); 0.27 (9H, s).

APCI-MS m/z: 223 [MH⁺].

c)1-({[(4S)-4-Methyl-2,5-dioxoimidazolidin-4-yl]methyl}sulfonyl)-1,2,3,6-tetrahydropyridin-4-yltrifluoromethanesulfonate

4-{[(Trifluoromethyl)sulfonyl]oxy}-1,2,3,6-tetrahydropyridinium chloridewas reacted with[(4S)-4-methyl-2,5-dioxoimidazolidin-4-yl]methanesulfonyl chloride(Example 1f) in the same way as for Example 1c.

¹H NMR (DMSO-d₆) δ 10.77 (1H, s), 8.04 (1H, d), 6.10 (1H, t), 3.88 (2H,q), 3.36-3.58 (4H, m), 2.50-2.56 (2H, m), 1.32 (3H, s).

APCI-MS m/z: 422 [MH⁺].

d) 4-{[(Trifluoromethyl)sulfonyl]oxy}-1,2,3,6-tetrahydropyridiniumchloride

tert-Butyl4-{[(trifluoromethyl)sulfonyl]oxy}-3,6-dihydropyridine-1(2H)-carboxylate(3.77 g, 11.4 mmol) was mixed with THF (15 mL) and concentratedhydrochloric acid (15 mL). After 1 hour, the mixture was evaporated anddried by azeotropic evaporation with toluene and methanol to give abeige solid (88%) that could be used without further purification.

¹H NMR (CDCl₃) δ 9.72 (2H, s), 6.22 (1H, s), 3.75 (2H, q), 3.30 (2H, t),2.65 (2H, td),

APCI-MS m/z: 232 [MH⁺].

e) tert-Butyl 4-{[(trifluoromethyl)sulfonyl]oxy}-3,6-dihydropyridine-1(2H)-carboxylate

A solution of N-boc-piperidin-4-one (10.14 g, 50 mmol) in THF (80 mL)was added to a cooled solution (−78° C.) of 2M LDA in THF (30 mL, 60mmol, 1.2 eq.) and THF (80 mL) over approximately 30 minutes. Afterstirring a further 10 minutes, a solution of1,1,1-trifluoro-N-phenyl-N-[(trifluoromethyl)sulfonyl]methanesulfonamide(20 g, 56 mmol, 1.1 eq.) in THF (80 mL) was added and the mixture wasallowed to warm to room temperature. The solution was washed with water,the aqueous layer washed with EtOAc (×2), organic phases combined andwashed with saturated ammonium chloride solution, brine, dried (sodiumsulphate) and evaporated. The residue was filtered through neutralAlumina (200 g) eluting with n-heptane followed by n-heptane/EtOAc 9:1.After evaporation the showed some triflating agent still present but thecrude product was used without further purification. Yield (13.17 g,79.5%). (Wustrow, D. J., Synthesis, 1991, 993-995).

¹H NMR (CDCl₃) δ 5.77 (1H, s), 4.05 (2H, q), 3.64 (2H, t), 2.45 (2H,quintet), 1.48 (9H, s).

GCMS-MS m/z: 274 [M-57].

EXAMPLE 3(5S)-5-Methyl-({[4-{[2-(trifluoromethyl)pyrimidin-5-yl]ethynyl}-3,6-dihydropyridin-1(2H)-yl]sulfonyl}methyl)imidazolidine-2,4-dione

The title compound was prepared in 48% yield from2-(trifluoromethyl)-5-[(trimethylsilyl)ethynyl]pyrimidine by the samemethod as described for Example 2. White solid from 95% EtOH, decomp.240-245° C.

¹H NMR (DMSO-d₆) δ 10.8 (1H, br s), 9.16 (2H, s), 8.05 (1H, s), 6.42(1H, m), 3.88 (2H, m), 3.56 (1H, d), 3.42 (1H, d), 3.32 (2H, m), 2.41(2H, m) and 1.33 (3H, s).

APCI-MS m/z: 444 [MH⁺].

a) 2-(Trifluoromethyl)-5-[(trimethylsilyl)ethynyl]pyrimidine

2-(Trifluoromethyl)pyrimidine-5-yl trifluoromethanesulfonate (0.45 g,1.5 mmol) and dry triethylamine (1.0 mL) were mixed in a screw-cap vial.The solution was purged with dry argon for 10 minutes.Trimethylsilylacetylene (0.43 mL, 3.0 mmol), finely ground CuI (0.010 g,0.05 mmol) and PdCl₂(PPh₃)₂ (0.020 g, 0.030 mmol) were added. The vialwas sealed and heated in an aluminum block at 80° C. After stirring for5 hours the volatiles were evaporated at room temperature (the productsublimes at 35-40° C./10 mbar). The black residue was taken up in EtOAc(20 mL) and concentrated with silica (about 5 to 10 g) to dryness. Flashchromatography on silica with EtOAc/heptane (1:30) afforded2-(trifluoromethyl)-5-[(trimethylsilyl)ethynyl]pyrimidine as a whitesolid (0.35 g, 95%), m.p. 75.5-76.0° C.

¹H NMR (CDCl₃) δ 8.90 (2H, s) and 0.30 (9H, s).

APCI-MS m/z: 245 [MH⁺].

b) 2-(Trifluoromethyl)pyrimidine-5-yl trifluoromethanesulfonate

Triflic anhydride (1.01 mL, 6.0 mmol) was added dropwise to a stirredmixture of 2-(trifluoromethyl)pyrimidin-5-ol (prepared according to U.S.Pat. No. 4,558,039) (0.82 g, 5.0 mmol), toluene (10 mL) and aqueoustripotassium phosphate (30% by weight, 10 mL) at ice-bath temperature(Frantz et al., Organic Letters, 2002, 4(26), 4717-4718). When theaddition was complete the ice-bath was taken away and the solution wasstirred at ambient temperature for 30 minutes. The clear phases wereseparated and the organic layer was washed with water, then brine.Drying of the organic phase over anhydrous sodium sulfate, filtrationand concentration by rotary evaporation at room temperature afforded2-(trifluoromethyl)-pyrimidine-5-yl trifluoromethanesulfonate as acolourless oil (1.38 g, 93%). B.p. 75-77° C. (10 mbar).

¹H NMR (CDCl₃) δ 8.90 (2H, s).

EXAMPLE 4(5S)-5-Methyl-5-({[4-[(2-methylpyrimidin-5-yl)ethynyl]-3,6-dihydropyridin-1(2H)-yl]sulfonyl}methyl)imidazolidine-2,4-dione

tert-Butyl4-[(2-methylpyrimidin-5-yl)ethynyl]-3,6-dihydropyridine-1(2H)-carboxylatewas treated with TFA in EtOH and after completion of the reaction thesolvent was evaporated and the mixture was freeze dried. The residue wastaken up in DMF (1.5 mL) and the mixture was cooled to 4° C.N-Ethyldiisopropylamine (2.2 eq.) was added and the mixture was stirredfor 20 minutes before adding[(4S)-4-methyl-2,5-dioxoimidazolidin-4-yl]methanesulfonyl chloride(Example 1f) (1.1 eq.) in DMF (1 mL). The mixture was stirred for 10 minat 4° C. and then stirred for 2 h at room temperature before the solventwas evaporated. The product was purified by preparative HPLC to give thetitle compound (0.022 g, 30%).

¹H NMR (DMSO-d₆); 10.75 (1H, s); 8.80 (2H, s); 8.02 (1H, s); 7.80 (1H,m); 7.32 (1H, d, J=8.1 Hz); 6.24 (1H, s); 3.81 (2H, d, J=3.2 Hz);3.34-3.21 (2H, m); 3.30 (3H, s); 2.75 (2H, q, J=20.8 Hz); 2.34 (2H, m);1.29 (3H, s); 1.19 (3H, t, J=7.6 Hz).

APCI-MS m/z: 390 [MH⁺].

a) 2-Methyl-5-[(trimethylsilyl)ethynyl]pyrimidine

5-Bromo-2-methyl-pyrimidine (prepared according to UK patent applicationGB 2 157 288) (0.2 g, 1.16 mmol), (trimethylsilyl)acetylene (164 μL, 1.3mmol), CuI (0.022 g, 0.116 mmol) and PdCl₂(PPh₃)₂ (0.082 g, 0.116 mmol)in Et₃N (2 mL) and THF (2 mL) were stirred at 80° C. for 4 h. Aftercooling, the solvents were removed under vacuum and the residuechromatographed to give the subtitle compound (0.16 g, 50%).

APCI-MS m/z: 191 [MH⁺].

b) tert-Butyl4-[(2-methylpyrimidin-5-yl)ethynyl]-3,6-dihydropyridine-1(2H)-carboxylate

To a solution of CuCl (1 mg, 0.01 mmol) and PdCl₂(PPh₃)₂ (0.003 g, 0.004mmol) in DMF (2 mL) were added2-methyl-5-[(trimethylsilyl)ethynyl]pyrimidine (0.088 g, 0.462 mmol) andtert-butyl4-{[(trifluoromethyl)sulfonyl]oxy}-3,6-dihydropyridine-1(2H)-carboxylate(Example 2e) (0.183 g, 0.555 mmol) at room temperature. The reactionmixture was stirred for 8 h at 80° C. After cooling, the mixture wasquenched with 1N HCl and extracted with ether (3×). The combined organiclayers were washed with saturated aqueous NaHCO₃ solution, brine anddried. Filtration and evaporation afforded a brown oil, which waspurified on HPLC to give the subtitle compound (0.062 g, 45%).

APCI-MS m/z: 300 [MH⁺].

EXAMPLE 5(5S)-5-({[4-[(2-Ethylpyrimidin-5-yl)ethynyl]-3,6-dihydropyridin-1(2H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione trifluoroacetate

The title compound was made in the same way as described for Example 4.The 5-bromo- 2-ethyl-pyrimidine starting material was prepared using themethodology of GB 2 157 288.

¹H NMR (DMSO-d₆); 10.75 (1H, s); 8.82 (2H, s); 8.05 (1H, s); 6.24 (1H,s); 3.81 (2H, d, J=3.2 Hz); 3.34-3.21 (2H, m); 3.30 (3H, s); 2.92 (2H,q, J=17.8 Hz); 2.75 (2H, q, J=20.8 Hz); 2.34 (2H, m); 1.26 (3H, t,J=12.8 Hz); 1.19 (1H, s).

APCI-MS m/z: 404 [MH⁺].

EXAMPLE 6(5S)-5-({[4-[(2-Methoxypyrimidin-5-yl)ethynyl]-3,6-dihydropyridin-1(2H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione

The title compound was prepared from 5-bromo-2-methoxypyrimidine and(5S)-5-{[(4-ethynyl-3,6-dihydropyridin-1(2H)-yl)sulfonyl]methyl}-5-methylimidazolidine-2,4-dionein the same way as described in Example 1.

¹H NMR (DMSO-d₆): δ 10.75 (1H, s); 8.73 (2H, s); 8.04 (1H, s); 6.26 (1H,s); 3.95 (3H, s); 3.81 (2H, d, J=3.2 Hz); 3.34-3.21 (2H, m); 3.30 (3H,s); 2.75 (2H, q, J=20.8 Hz); 2.34 (2H, m); 1.19 (3H, t, J=7.6 Hz).

APCI-MS m/z: 406 [MH⁺].

PHARMACOLOGICAL EXAMPLE

Isolated Enzyme Assays

MMP12

Recombinant human MMP 12 catalytic domain may be expressed and purifiedas described by Parkar A. A. et al, (2000), Protein Expression andPurification, 20, 152. The purified enzyme can be used to monitorinhibitors of activity as follows: MMP12 (50 ng/ml final concentration)is incubated for 60 minutes at room temperature with the syntheticsubstrate Mca-Pro-Cha-Gly-Nva-His-Ala-Dpa-NH₂ (10 μM) in assay buffer(0.1M “Tris-HCP” (trade mark) buffer, pH 7.3 containing 0.1M NaCl, 20 mMCaCl₂, 0.020 mM ZnCl and 0.05% (w/v) “Brij 35” (trade mark) detergent)in the presence (10 concentrations) or absence of inhibitors. Activityis determined by measuring the fluorescence at λex 320 nm and λem 405nm. Percent inhibition is calculated as follows:% Inhibition is equal to the[Fluorescence_(plus inhibitor)−Fluorescence_(background)] divided by the[Fluorescence_(minus inhibitor)−Fluorescence_(background)].MMP8

Purified pro-MMP8 is purchased from Calbiochem. The enzyme (at 10 μg/ml)is activated by p-amino-phenyl-mercuric acetate (APMA) at 1 mM for 2.5h, 35° C. The activated enzyme can be used to monitor inhibitors ofactivity as follows: MMP8 (200 ng/ml final concentration) is incubatedfor 90 minutes at 35° C. (80% H₂O) with the synthetic substrateMca-Pro-Cha-Gly-Nva-His-Ala-Dpa-NH₂ (12.5 μM) in assay buffer (0.1M“Tris-HCl” (trade mark) buffer, pH 7.5 containing 0.1M NaCl, 30 mMCaCl₂, 0.040 mM ZnCl and 0.05% (w/v) “Brij 35” (trade mark) detergent)in the presence (10 concentrations) or absence of inhibitors. Activityis determined by measuring the fluorescence at λex 320 nm and λem 405nm. Percent inhibition is calculated as follows:% Inhibition is equal to the[Fluorescence_(plus inhibitor)−Fluorescence_(background)] divided by the[Fluorescence_(minus inhibitor)−Fluorescence_(background)].MMP9

Recombinant human MMP9 catalytic domain was expressed and then purifiedby Zn chelate column chromatography followed by hydroxamate affinitycolumn chromatography. The enzyme can be used to monitor inhibitors ofactivity as follows: MMP9 (5 ng/ml final concentration) is incubated for30 minutes at RT with the synthetic substrateMca-Pro-Cha-Gly-Nva-His-Ala-Dpa-NH₂ (5 μM) in assay buffer (0.1 M“Tris-HCl” (trade mark) buffer, pH 7.3 containing 0.1M NaCl, 20 mMCaCl₂, 0.020 mM ZnCl and 0.05% (w/v) “Brij 35” (trade mark) detergent)in the presence (10 concentrations) or absence of inhibitors. Activityis determined by measuring the fluorescence at λex 320 nm and λem 405nm. Percent inhibition is calculated as follows:% Inhibition is equal to the[Fluorescence_(plus inhibitor)−Fluorescence_(background)] divided by the[Fluorescence_(minus inhibitor)−Fluorescence_(background)].MMP14

Recombinant human MMP 14 catalytic domain may be expressed and purifiedas described by Parkar A. A. et al, (2000), Protein Expression andPurification, 20, 152. The purified enzyme can be used to monitorinhibitors of activity as follows: MMP14 (10 ng/ml final concentration)is incubated for 60 minutes at room temperature with the syntheticsubstrate Mca-Pro-Cha-Gly-Nva-His-Ala-Dpa-NH₂ (10 μM) in assay buffer(0.1M “Tris-HCl” (trade mark) buffer, pH 7.5 containing 0.1M NaCl, 20 mMCaCl₂, 0.020 mM ZnCl and 0.05% (w/v) “Brij 35” (trade mark) detergent)in the presence (5 concentrations) or absence of inhibitors. Activity isdetermined by measuring the fluorescence at λex 320 nm and λem 405 nm.Percent inhibition is calculated as follows: % Inhibition is equal tothe [Fluorescence_(plus inhibitor)−Fluorescence_(background)] divided bythe [Fluorescence_(minus inhibitor)−Fluorescence_(background)].

A protocol for testing against other matrix metalloproteinases,including MMP9, using expressed and purified pro MMP is described, forinstance, by C. Graham Knight et al., (1992) FEBS Lett., 296(3),263-266.

MMP19

Recombinant human MMP19 catalytic domain may be expressed and purifiedas described by Parkar A. A. et al, (2000), Protein Expression andPurification, 20:152. The purified enzyme can be used to monitorinhibitors of activity as follows: MMP19 (40 ng/ml final concentration)is incubated for 120 minutes at 35° C. with the synthetic substrateMca-Pro-Leu-Ala-Nva-Dpa-Ala-Arg-NH₂ (5 μM) in assay buffer (0.1M“Tris-HCl ” (trade mark) buffer, pH 7.3 containing 0.1M NaCl, 20 mMCaCl₂, 0.020 mM ZnCl and 0.05% (w/v) “Brij 35” (trade mark) detergent)in the presence (5 concentrations) or absence of inhibitors. Activity isdetermined by measuring the fluorescence at λex 320 nm and λem 405 nm.Percent inhibition is calculated as follows: % Inhibition is equal tothe [Fluorescence_(plus inhibitor)−Fluorescence_(background)] divided bythe [Fluorescence_(minus inhibitor)−Fluorescence_(background)].

Protein Binding

Plasma protein binding was determined by ultrafiltration in an automated96 well format assay. On each test occasion the plasma protein bindingof a reference compound (budesonide) was monitored in parallel.

Test compounds (10 mM dissolved in DMSO) were added to plasma to a finalconcentration of 10 μM and equilibrated at room temperature for 10minutes. 350 μL of the plasma was transferred to an ultrafiltrationplate, Microcon-96 (10 kDa cutoff, Millipore). The ultrafiltration platewas centrifuged at 3000 G for 70 minutes at room temperature. Aftercentrifugation, the concentration of the compounds in the obtainedplasma water (the unbound fraction) was determined by LC-MS/MS using a3-point calibration curve and compared to the concentration in theoriginal spiked plasma.

The analyses were performed using a gradient chromatographic system withacetic acid/acetonitrile as mobile phases. The detection was done usinga triple quadropole mass spectrometer, API3000 or API4000, from AppliedBiosystems, with an electrospray interface.

Protocol for Determination of Solubility

The solubility of test compounds in 0.1M phosphate buffer, pH 7.4, wasdetermined as follows:

The test compound (1 mg) was weighed into a 2 mL glass vial with a screwcap and 0.1 M phosphate buffer pH 7.4. (1.00 mL) was added. The samplevial was then sonicated for about 10 minutes and then placed on a shakeboard overnight at 20° C. The contents of the sample vial were thenfiltered through a Millipore Millex-LH 0.45 μm filter into a new 2 mLglass vial to give a clear solution. The clear solution (40 μL) wastransferred to a new 2 mL glass vial and diluted with 0.1 M phosphatebuffer, pH 7.4 (960 μL).

A standard calibration curve for each particular test compound wasestablished using solutions of known concentration. These solutions ofknown concentration were normally chosen to have concentrations of ˜10μg/mL and ˜50 μg/mL. They were prepared by dissolving a known weight ofthe compound in 99.5% ethanol (500 μL) and then sonicating for oneminute if necessary. If the compound was still not completely dissolved,DMSO (500 μL) was added and the mixture sonicated for an additional oneminute. The resulting solution was then diluted to the appropriatevolume with a mixture of acetonitrile/100 mM ammonium acetate pH 5.520-50/80-50. If necessary, a further, more dilute, standard solution wasprepared by dilution.

Test compound solutions and standard solutions were then analysed byHPLC with UV-detection using the following parameters and the solubilityof the test compound in 0.1M phosphate buffer was thereby determined:

HPLC-equipment: HP1100/HP1050 Column: HyPURITY Advanced, 5 μm, 125 × 3mm Column temperature: RT Flow rate: 1 mL/min Mobile phase: A =acetonitrile B = 100 mM ammonium acetate pH 5.5 Isocratic ratio: A/B20-50/80-50 UV detector: 254 nm (220-280 nm) Injection volume: 20 μLChromatographic data ATLAS/Xchrome handling system:Protocol for Determination of Log D

Log D values at pH 7.4 were determined using a shake flask method. Anappropriate small amount of the test compound was placed in a 2 mL glassvial with a screw cap at room temperature and 600 μL of 1-octanol(saturated with 10 mM phosphate buffer pH 7.4) was added. The vial wasthen sonicated for one minute so as to dissolve the compound completely.Then 600 μL of 10 mM phosphate buffer pH 7.4 (saturated with 1-octanol)was added and the vial was shaken for 4 minutes to mix the two phases.The two phases were then separated by centrifugation of the sample at1000 g for 10 minutes at room temperature. Finally, the separatedaqueous and organic phases were analysed in duplicate by HPLC using thefollowing conditions:

Injector: Spark Holland, Endurance Pump: HP1050 Detector: Kratos,Spectroflow 783 Column: YMC Pro C18, 5 μm, 50 × 4 mm, Part no.AS12S050504QT Column temperature: RT Flow rate: 1 mL/min Mobile phase: A= acetonitrile B = 25 mM formic acid C = 100 mM ammonium acetate pH 5.5D = 0.05% ammonium acetate Gradient: 0.00 min A/B or A/C or A/D 5/955.00 min A/B or A/C or A/D 100/0 7.00 min A/B or A/C or A/D 100/0 7.02min A/B or A/C or A/D 5/95 UV detector: 254 nm Injection volume: 50 μLof undiluted aqueous phase and 5 μL of 10 times diluted (with methanol)organic phase Injection cycle time: 11 min Centrifuge: Hettich,Universal 30RF Vortex: Scientific Industries, Vortex-2 genieChromatographic data ATLAS/Xchrome handling system:

The log D_(pH7.4) value was automatically calculated (see equationbelow) by an Excel sheet after manual typing of compound peak arearesponses which were reported from the ATLAS chromatographic datahandling system.

Calculation of log D_(pH 7.4) by equation:

${{Log}\mspace{11mu} D} = {\left( \frac{\lbrack{Analyte}\rbrack_{org}}{\lbrack{Analyte}\rbrack_{aq}} \right) = {\log\left( \frac{{Area}_{org} \times {Dilution}\mspace{14mu}{factor}_{org}}{{Area}_{aq} \times {Dilution}\mspace{14mu}{factor}_{aq} \times \frac{V_{inj}({org})}{V_{inj}({aq})}} \right)}}$

The following table shows data for a representative selection of thecompounds of the present invention and for selected compounds from WO02/074767.

TABLE Solubility Protein hMMP12 hMMP9 hMMP8 hMMP14 hMMP19 pH 7.4 bindingCompound IC₅₀ (nM) IC₅₀ (nM) IC₅₀ (nM) IC₅₀ (nM) IC₅₀ (nM) (μM) (% free)Example 5 9 9 1,140 >10,000 >10,000 91 47 Example 3 6 5 547 >10,0007,900 118 33 Example 1 6 5 2,530 >10,000 >10,000 396 18 WO 02/074767,page 120 2 9 180 4,300 3,980 49 1.75 (5S)-5-({[4-[(4-chlorophenyl)ethynyl]- 3,6-dihydropyridin- 1(2H)-yl]sulfonyl}-methyl)-5-methyl- imidazolidine-2,4-dione WO 02/074767, page 120 3 34384 4,430 1,970 72 2.25 (5S)-5-methyl-5-({[4-[(4- methylphenyl)ethynyl]-3,6-dihydropyridin- 1(2H)-yl]sulfonyl}- methyl)imidazolidine- 2,4-dione

1. A compound selected from the group consisting of: (5S)-5-methyl-5-({[4-{[2-(methylthio)pyrimidin-5 -yl]ethynyl}-3,6-dihydropyridin-1(2H) -yl]sulfonyl}methyl)imidazolidine-2,4-dione; (5S)-5-methyl-5-({[4-{[2-(trifluoromethyl)pyrimidin -5-yl]ethynyl}-3,6-dihydropyridin-1(2H) -yl]sulfonyl}methyl)imidazolidine-2,4-dione; (5S)-5-methyl-5-({[4-[(2-methylpyrimidin-5-yl)ethynyl]-3,6-dihydropyridin-1(2H) -yl]sulfonyl}methyl)imidazolidine-2,4-dione; (5S)-5-({[4-[(2-ethylpyrimidin-5-yl)ethynyl]-3,6-dihydropyridin-1(2H)-yl]sulfonyl}methyl)-5-methylimidazolidine-2,4-dione; and (5S)-5-({[4-[(2-methoxypyrimidin-5-yl)ethynyl]-3,6-dihydropyridin-1(2H)-yl]sulfonyl}methyl) -5-methylimidazolidine-2,4-dione; and pharmaceutically acceptable salts thereof.
 2. A pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof as claimed in claim 1 in association with a pharmaceutically acceptable adjuvant, diluent or carrier. 